The design of ovens such as coke ovens usually incorporates a standpipe by means of which gases are taken off the ovens. These standpipes form an acute angle or elbow sometimes known as a "goose neck." The gases from the standpipe are carried over to a collector main, where all of such gases are then collected and passed to recovery equipment, scrubbers and the like for further processing before they are vented to atmosphere.
The gases in the individual standpipes are at extremely high temperatures in the region of 2,000.degree. F or more. Such gases are heavily ladened with entrained solids, and carbon, tar and the like. Such entrained solids and tar fractions adhere to the sides of the standpipe and rapidly accumulate and build up thereby blocking passage of gases through the standpipe. As a result, the efficiency of the ovens is greatly reduced, and substantial volumes of untreated gases will leak to atmosphere causing pollution problems and health hazards. Such gas losses also reduce the efficiency of the recovery operations.
It is therefore necessary that the standpipes be cleaned out frequently to avoid accumulations of such solids. In the past, it has been the practice to employ various forms of mechanical cleaning equipment including for example jack hammers or hydraulic scrapers. Typical examples of such equipment are shown in U.S. Pat. No. 3,196,088 Coleman and U.S. Pat. No. 3,400,052 Olsen. However, such mechanical cleaners had severe disadvantages. In the first place, they had to be operated from remote control, due to the great heat of the exiting gases. Unless such equipment was operated with great precision, the cleaning was performed in an inefficient manner. In addition, the solids become encrusted and impacted and are extremely hard. As a result considerable force must be used to remove them. However, if too much force is applied by such mechanical cleaners then the standpipes become damaged.
Accordingly, such equipment is regarded as unsatisfactory and it is clearly desirable to provide some improved apparatus for cleaning such standpipes.